This invention relates to an improved bolt retainer for use as a component of an access panel fastener for securing a panel to a structure.
Copending Basile U.S. Pat. No. 4,125,140, and assigned to the same assignee as the present application, discloses an access panel fastener which includes as a component thereof a bolt retainer adapted to be mounted in an aperture through a panel which is to be secured to a structure by the access panel fastener. Said Basile U.S. Pat. No. 4,125,140 access panel fastener includes, in addition to the retainer, a bolt of a particular configuration and a nut assembly. The nut assembly is mounted on the structure aligned with an aperture therethrough and the bolt is intended to be permanently captured by the retainer and is movable axially relative to the retainer between a securing or clamping position in which the bolt may engage the nut assembly and a hold-out position.
More particularly, the retainer of said Basile U.S. Pat. No. 4,125,140 is ring-like and comprises an annular body and a disc which cooperate to provide an aperture extending through the retainer. The retainer of said Basile U.S. Pat. No. 4,125,140 also includes three discrete bolt engaging jaws located in the aperture for movement in radial directions. Each of the three jaws is a segment of a generally annular configuration and is of uniform thickness, having opposite plane faces perpendicular to the retainer axis. Finally, the retainer of said Basile U.S. Pat. No. 4,125,140 includes a cochlear spring which surrounds the three jaws and biases the same toward the retainer axis and into engagment with the bolt to hold the same in the hold-out position in which the jaws are minimally spaced from the retainer axis and circumferentially from each other. The bolt is readily movable from the hold-out position to the clamping position in which the bolt engages the nut assembly and the jaws are maximally spaced from the retainer axis and circumferentially from each other.
Two problems have occasionally arisen with the retainer of said Basile U.S. Pat. No. 4,125,140.
First, with no bolt present, two of the three jaws of said Basile U.S. Pat. No. 4,125,140 may be accidentally held maximally spaced from the retainer axis and circumferentially from each other. With the parts in this condition, the third jaw can readily fall out of the retainer body, resulting in failure of the access panel fastener.
Second, the jaws of said Basile U.S. Pat. No. 4,125,140 can move to the fully opened position by radial pressure applied in either axial direction. Thus, the bolt can be pulled through the jaws over a shoulder of the bolt with a quick, wrenching motion of the bolt, thus undesirably disengaging the bolt from the retainer.
The first of these problems with the retainer of said Basile U.S. Pat. No. 4,125,140 is overcome by the present invention by replacing the three jaws, each of which is roughly 120.degree. in circumferential extent, with two jaws each of which is of larger dimensions than each of the three jaws.
The second of these problems with the retainer of said Basile U.S. Pat. No. 4,125,140 is overcome by providing each jaw with a flanged portion or boss which engages the wall of the retainer aperture when the bolt is pulled in the axial direction which tends to remove the bolt from the retainer, the engagement of the jaw bosses with the retainer aperture limiting the opening of the jaws to an intermediate position in which the shoulder of the bolt is prevented from passing between the jaws.
Accordingly, an important general object of the present invention is to provide a retainer for an access panel fastener which is an improvement over that of said Basile U.S. Pat. No. 4,125,140.
It is an important specific object to provide an improved access panel fastener retainer having jaws which can not become dislodged from the retainer.
It is another important specific object to provide an improved access panel fastener retainer having jaws with means for limiting the opening of the jaws to an intermediate position in which the shoulder of the bolt can not pass between the jaws, thus preventing the bolt from being disassembled from the retainer.
It has been found, too, that with the retainer of said Basile U.S. Pat. No. 4,125,140, the jaws tend to cause wear of the bolt threads, such wear limiting the effective life of the access panel fastener, which must be reusable over many reuses. The increased axial thickness of the jaws of the present application, provided by the jaw bosses, minimizes such bolt thread wear and increases the life of the access panel fastener.
It is therefore another important object to provide a retainer for an access panel fastener resulting in increased bolt life, thus increasing the life of the access panel fastener.